Did Joseph Armstrong heal people of smallpox?

We have been asked to determine the basis for an account claiming that Joseph Armstrong (1847–1907) was quarantined with people suffering from smallpox, and that he healed several of them through Christian Science. (James A. Neal, another early Christian Scientist, is sometimes incorrectly named in connection with this report.)

Longyear Museum¹ holds papers related to Joseph Armstrong and his wife, Mary Armstrong, in its archives.² A 1975 Longyear newsletter profiled the Armstrongs³ and included this:

After completing the Normal Course [at the Massachusetts Metaphysical College founded by Mary Baker Eddy] the Armstrongs devoted full time to the Cause of Christian Science preaching the truth they had been taught and doing pioneer healing work in the midwest. The Armstrongs practiced in Kansas and Ohio. Mr. and Mrs. Armstrong’s cards appeared in The Christian Science Journal for the first time in 1888. During this period Joseph was maliciously confined to a smallpox pest house in Salina, Kansas, for six weeks. His understanding of Christian Science enabled him not only to provide protection against this disease, but to heal several cases of smallpox while there. He gained his release by evidencing perfect health which several doctors confirmed after rigid examination.

This account also appears in The Onward and Upward Chain: Pioneers of Christian Science in the 1880s, a 2004 Longyear film:

One time while passing through Salina, Kansas, Joseph was locked up six weeks in a pest house for smallpox, maliciously, according to his wife. While confined there he healed four cases of smallpox and forced his release by manifest evidence of perfect health, coming out untouched by the belief, after undergoing a rigid examination by several doctors.⁴

Joseph Armstrong was born in Carrollton, Illinois. He became interested in Christian Science in 1884, when his wife received Christian Science treatment from Silas J. Sawyer, a student of Mary Baker Eddy. In 1886 he studied Christian Science with Janet T. Colman. He went on to study under Eddy in her 1887 Primary class,1888 Obstetrics class, and 1889 Normal class. Armstrong joined the Christian Scientist Association in December 1887 and became a member of The First Church of Christ, Scientist, on December 31, 1892. After teaching and practicing in the Midwest, the Armstrongs moved to Boston, where he served on the Christian Science Board of Directors (1893–1907) and as publisher of Eddy’s writings (1896–1907).